Open pilot study of a guided digital self-help intervention targeting sleep and the biological clock in university students using a pre-test post-test design.

Insomnia is common among university students and is associated with mental health problems. Students often have irregular day/night rhythms, which contribute to circadian rhythm disruptions. This open pilot study investigated the feasibility, acceptability, and preliminary effectiveness of a 5-week digital guided self-help intervention in university students with self-reported insomnia. The intervention is based on cognitive behavioural therapy for insomnia with specific emphasis on the biological clock ('i-Sleep & BioClock'). We assessed feasibility and acceptability. Pre- to post-intervention (7-week) changes in insomnia, depression, anxiety, chronotype, and quality of life were evaluated. Of 101 included students, 81 accessed the platform, 41 initiated the intervention, and 13 completed the intervention. Post-test response was 39%. Students rated the intervention with good acceptability and the platform with excellent usability. Study completers (n = 39) showed large improvements in insomnia severity (p < 0.001, d = 1.04), and moderate improvements in depression (p < 0.001, d = 0.63), anxiety (p < 0.001, d = 0.35), and functioning (p < 0.001, d = 0.56). No significant changes were found in quality of life (p = 0.07, d = 0.19). To summarize, the intervention had low uptake but moderate adherence and fairly good acceptability along with important improvements in sleep, mental health, and functioning.Trial registration: ClinicalTrials.gov: NCT05363995.